Inactivation of dipeptidyl peptidase IV attenuates the virulence of Streptococcus suis serotype 2 that causes streptococcal toxic shock syndrome.

Di-peptidyl peptidase IV (DPP IV), originally recognized as CD26 in eukaryotic cells, is distributed widely in microbial pathogens, including Streptococcus suis (S. suis), an emerging zoonotic agent. However, the role of DPP IV in S.

The orphan response regulator CovR: a globally negative modulator of virulence in Streptococcus suis serotype 2.

Streptococcus suis serotype 2 is an emerging zoonotic pathogen responsible for a wide range of life-threatening diseases in pigs and humans. However, the pathogenesis of S. suis serotype 2 infection is not well understood.

Extensor digitorum brevis and extensor hallusis brevis transplantation for treatment of long-standing facial paralysis.

Objective: To evaluate the efficacy of free transplantation of denervated muscles and vessels in the treatment of long-standing facial paralysis.

Methods: A total of 26 patients with facial paralysis (10 males and 16 females, aged 16-65 years, mean: 47 years) were enrolled in this study to receive transplantation of denervated extensor digitorum brevis (EDB) and extensor hallusis brevis (EHB). The muscle tendon was slung to the ala nasi, the middle point of the nasolabial sulcus, the angulus oris and the chin to correct the nasal and oral deformity.

[Ferumoxide labeled Flk1+ CD31- CD34- human bone marrow mesenchymal stem cells and its in vivo tracing in the brains of Macaca Fascicularis].

Objective: To explore the method for labeling Flk1+ CD31- CD34- human bone marrow mesenchymal stem cells (hBMSCs) with ferumoxide-PLL and evaluate the feasibility of its tracing after transplantation into the brains of Macaca Fascicularis.

Methods: The hBMSCs were incubated with ferumoxide-PLL. Trypan blue staining, Prussian blue staining, and transmission electron microscope were performed to show intracellular iron, marking efficiency, and the vigor of the labeled cells.

Identification and experimental verification of protective antigens against Streptococcus suis serotype 2 based on genome sequence analysis.

Streptococcus suis serotype 2 (S. suis 2) is an important zoonotic pathogen that can cause severe disease and even death in both humans and swine. No effective vaccine is clinically available.

[Construction of RevS gene knock-out mutant of Streptococcus suis serotype 2].

Objective: To construct a gene knock-out mutant of response regulator named RevS in Streptococcus suis serotype 2 virulent strain 05ZYH33, and to investigate the effects of its deletion on the biological characters of this pathogen and the pathogenesis to mice and piglets.

Methods: Recombinant gene knock-out vector consisting of Spc(r) cassette was constructed and flanking was constructed consisting of Spc(r) cassette with flanking homology regions to the RevS genes while the isogenic RevS-deficient mutant was screened by allelic replacement. The effects of RevS deletion on the basic biological characters of 05ZYH33 including growth stability, colonial morphology, haemolysis, Gram staining, growth curve and protein expression were examined in vitro.

Functional definition and global regulation of Zur, a zinc uptake regulator in a Streptococcus suis serotype 2 strain causing streptococcal toxic shock syndrome.

Zinc is an essential trace element for all living organisms and plays pivotal roles in various cellular processes. However, an excess of zinc is extremely deleterious to cells. Bacteria have evolved complex machineries (such as efflux/influx systems) to control the concentration at levels appropriate for the maintenance of zinc homeostasis in cells and adaptation to the environment.

The involvement of sortase A in high virulence of STSS-causing Streptococcus suis serotype 2.

Sortase A (SrtA), originally identified as a transpeptidase in Staphylococcus aureus, plays key roles in full virulence of pathogenic bacteria. In silico genome-wide search suggested a srtA homologue from 05ZYH33, a Chinese human isolate of streptococcal toxic shock syndrome (STSS)-causing Streptococcus suis serotype 2 (S. suis 2, SS2).

[Study on molecular epidemiology of major pathogenic Streptococcus suis serotypes in middle part of Jiangsu province].

Objective: To determine the prevalence of Streptococcus suis and major pathogenic serotypes in middle part of Jiangsu province.

Methods: Tonsillar specimens from 303 slaughtered pigs aged 6 to 8 months were investigated for the presence of Streptococcus suis and major pathogenic serotypes by polymerase chain reaction (PCR) method. Bacteriological examination compared with molecular genetics identification for three Streptococcus suis isolates were also done.

SalK/SalR, a two-component signal transduction system, is essential for full virulence of highly invasive Streptococcus suis serotype 2.

Background: Streptococcus suis serotype 2 (S. suis 2, SS2) has evolved into a highly infectious entity, which caused the two recent large-scale outbreaks of human SS2 epidemic in China, and is characterized by a toxic shock-like syndrome. However, the molecular pathogenesis of this new emerging pathogen is still poorly understood.

Existence and characterization of allelic variants of Sao, a newly identified surface protein from Streptococcus suis.

Surface antigen one (Sao) is a newly identified protein from the major zoonotic pathogen, Streptococcus suis. In search of functional proteins related to the pathogenesis of Chinese S. suis 2 (SS2), unexpectedly, a variant of Sao protein was obtained.

[Homologous analysis of Streptococcus suis srt gene and prokaryotic expression of srtA].

Aim: To elucidate the distribution of srt gene in the genome of S.suis 05ZYH33, prokaryotically express Sortase A and analyze its antigenicity.

Methods: Homologous genes encoding sortase family members were analyzed, and then the srtA gene of S.

A glimpse of streptococcal toxic shock syndrome from comparative genomics of S. suis 2 Chinese isolates.

Background: Streptococcus suis serotype 2 (SS2) is an important zoonotic pathogen, causing more than 200 cases of severe human infection worldwide, with the hallmarks of meningitis, septicemia, arthritis, etc. Very recently, SS2 has been recognized as an etiological agent for streptococcal toxic shock syndrome (STSS), which was originally associated with Streptococcus pyogenes (GAS) in Streptococci. However, the molecular mechanisms underlying STSS are poorly understood.

Preparation of recombinant antigen of O. tsutsugamushi Ptan strain and development of rapid diagnostic reagent for scrub typhus.

Spring scrub typhus has frequently occurred in Pingtan Island, China, since 2000. In this study, we amplified a 1352-bp DNA fragment encoding a truncated 56-kDa outer membrane protein of the Ptan strain, which was isolated from a serum sample of a patient with spring scrub typhus, and cloned it into the pET28a vector for expression. The expression product was a recombinant polypeptide containing a His-tag to facilitate purification on a Ni2+ chromatography column.

Streptococcal toxic shock syndrome caused by Streptococcus suis serotype 2.

Background: Streptococcus suis serotype 2 (S. suis 2, SS2) is a major zoonotic pathogen that causes only sporadic cases of meningitis and sepsis in humans. Most if not all cases of Streptococcal toxic shock syndrome (STSS) that have been well-documented to date were associated with the non-SS2 group A streptococcus (GAS).

[Cloning and prokaryotic expression of truncated muramidase-released protein gene of human Streptococcus suis type 2].

Aim: To clone and express the truncated Habb mrp gene of human Streptococcus suis type 2 (S.suis 2) and detect its activity.

Methods: A pair of primers based on S.

[Detection of virulence-associated factors of Streptococcus suis by multiplex PCR assay].

Objective: To rapidly and sensitively detect the four virulence-associated factors of Streptococcus suis, a multiplex PCR was developed.

Methods: In the process of this reaction, four distinct DNA targets were amplified. One target was based on the serotype 2 (and 1/2) specific cps gene and the others were based on Streptococcus suis mrp, epf (epf*) and sly gene, encoding the MRP, EF(EF*) and Sly proteins of Streptococcus suis.

[Screening and identification of mimic epitopes of monoclonal antibodies against hantaan virus using phage display technique].

Aim: To obtain mimic epitopes of monoclonal antibody (mAb) against Hantaan virus, and identify preliminarily their immunological characteristics.

Methods: Group-specific mAbs F3 and B11 were used as selective molecules for biopanning. After biopanning, the positive phages were identified by ELISA and DNA sequencing.